# llms.txt Availability Decision Check

> llms.txt Availability Decision Check is a paid API for AI agents from agentreadiness.halowerk.com, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-14).

Fetches public evidence from a target URL or domain and evaluates whether a valid llms.txt file is available, returning a structured verdict with observation, threshold, evidence source, limitations, and recommended action.

## Facts

- Endpoint: POST https://agentreadiness.halowerk.com/v1/llms-txt-decision?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/llms-txt-availability-decision-check-5107d8ca
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_QkmMfk-53s_Tdo1az_iZK

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability llms-txt-availability-decision-check-5107d8ca -d '<json body>'
```

Example prompt: Can you check whether example.com has an llms.txt file available and give me a verdict on whether it meets the standard — including where you found the evidence and any limitations?

## When to prefer this

Use this endpoint when you need a passive, non-invasive check of whether a specific domain or URL exposes a valid llms.txt file for AI agent discoverability. Prefer this over general crawl or SEO audit tools when you specifically need a structured verdict aligned to the llms.txt standard, with evidence sourcing and actionable next steps. Ideal for pre-integration checks, compliance monitoring, or competitive auditing of AI readiness.

## Known failure modes

- Target URL is unreachable or returns non-200 status — verdict may be 'fail' with a network error observation
- Domain normalized to HTTPS but site only serves HTTP — may result in false negative
- llms.txt present but malformed — observation may note file exists but verdict may still fail
- Rate limiting or bot blocking on the target site — evidence fetch may be incomplete
- compare_url or baseline provided but incompatible format — ignored or causes schema error

## How this service works

llms.txt available decision fetches current public evidence from the supplied target and evaluates the documented criterion. It returns the observation, threshold, verdict, exact evidence source, limitations and a mode-specific action. The check is passive: no login attempt, payload injection, exploit, purchase, form submission or load test is performed.

## Output

Returns a structured JSON object containing: the observation (what was found at the target), the threshold being evaluated, a pass/fail verdict, the exact evidence source URL, any limitations of the passive check, and a mode-specific recommended action. No login, form submission, or exploit is performed.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "target": {
   "type": "string",
   "maxLength": 2048,
   "minLength": 3,
   "description": "Public HTTP(S) URL or domain to inspect. A bare domain is normalized to HTTPS."
  },
  "context": {
   "type": "object",
   "description": "Optional non-secret correlation labels returned unchanged only in the request lifecycle.",
   "maxProperties": 12,
   "additionalProperties": {
    "type": [
     "string",
     "number",
     "boolean",
     "null"
    ]
   }
  },
  "baseline": {
   "type": [
    "object",
    "null"
   ],
   "description": "Optional baseline returned by a previous snapshot call.",
   "additionalProperties": true
  },
  "compare_url": {
   "type": "string",
   "maxLength": 2048,
   "minLength": 3,
   "description": "Optional public comparison URL. Used by change and monitoring services."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/llms-txt-availability-decision-check-5107d8ca/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agentreadiness.halowerk.com](https://www.zero.xyz/host/agentreadiness.halowerk.com/llms.txt)